A viewing optic is disclosed. In one embodiment, the viewing optic is a rifle scope having a scope body, a movable optical element defining an optical axis connected to the scope body, a turret and a zero point adjustment subassembly. The turret includes a turret screw, a turret chassis subassembly and a turret cap. The turret screw defines a screw axis and is operably connected to the optical element for adjusting the optical axis in response to rotation of the screw. The turret cap at least partially overlaps the turret chassis subassembly. The zero point adjustment subassembly includes a zero cap connected to the turret screw and a locking mechanism. The locking mechanism releasably secures the zero cap and the turret. The zero point adjustment subassembly permits adjustment of the zero point without the use of tools.

A reflector sight (2) for a portable firearm has an optical system for generating a natural image of a target region, a display (4) for reproducing an electronic image of the target region created by an electronic image creation unit and a beam splitter cube (6) for overlaying the natural image with the electronic image of the target region reproduced by the display (4). According to the invention, the display (4) is arranged on a first flat face (10) of beam splitter cube (6), to which fiat face a correction lens (12) is connected (12), the face (14) of which facing the display is convex, wherein a mirror lens element (18) is connected to a second flat face (16) of the beam splitter cube, the mirrored face (20) of which mirror lens element facing away from the beam splitter cube (6) is convex and aspherical and wherein the beam splitter cube (6), the correction lens (12) and the mirror lens element (18) form a correction block that consists of silica glass and/or.

Disposed are an extrinsic parameter calibration device and method for multiple camera devices, a storage medium and electronic device. The device includes: a plurality of mobile calibration plates, configured to calibrate extrinsic parameters of all camera devices carried on a mobile carrier which is disposed in a set space, wherein each mobile calibration plate is disposed on a slide rail disposed on a wall in the set space; and a control device, configured to control each of the mobile calibration plates to slide along the slide rail corresponding to the mobile calibration plate. In this disclosure, extrinsic parameters of camera devices disposed on mobile carrier are simultaneously calibrated by disposing a plurality of mobile calibration plates in the set space, thereby improving anti-noise and anti-interference capabilities of calibration, having strong robustness, effectively improving calibration efficiency and accuracy of calibration result, and also saving costs and time of calibration.

Metrology tools and methods are provided, which estimate the effect of topographic phases corresponding to different diffraction orders, which result from light scattering on periodic targets, and adjust the measurement conditions to improve measurement accuracy. In imaging, overlay error magnification may be reduced by choosing appropriate measurement conditions based on analysis of contrast function behavior, changing illumination conditions (reducing spectrum width and illumination NA), using polarizing targets and/or optical systems, using multiple defocusing positions etc. On-the-fly calibration of measurement results may be carried out in imaging or scatterometry using additional measurements or additional target cells.

Metrology tools and methods are provided, which estimate the effect of topographic phases corresponding to different diffraction orders, which result from light scattering on periodic targets, and adjust the measurement conditions to improve measurement accuracy. In imaging, overlay error magnification may be reduced by choosing appropriate measurement conditions based on analysis of contrast function behavior, changing illumination conditions (reducing spectrum width and illumination NA), using polarizing targets and/or optical systems, using multiple defocusing positions etc. On-the-fly calibration of measurement results may be carried out in imaging or scatterometry using additional measurements or additional target cells.

In general, techniques are described for a personal protective equipment (PPE) management system (PPEMS) that uses images of optical patterns embodied on articles of personal protective equipment (PPEs) to identify safety conditions that correspond to usage of the PPEs. In one example, an article of personal protective equipment (PPE) includes a first optical pattern embodied on a surface of the article of PPE; a second optical pattern embodied on the surface of the article of PPE, wherein a spatial relation between the first optical pattern and the second optical pattern is indicative of an operational status of the article of PPE.

A calibration method for a system for powder bed-based generating of three-dimensional components by means of electromagnetic radiation, in particular such as a PBLS system, having a radiation source deflection unit and a raisable and lowerable carrier plate, above which a component is built, where, in order to calibrate the radiation source deflection unit, at least one virtual reference mark is used and, by means of a detector, a target-actual deviation between the virtual reference mark and a beam of the radiation source deflection unit is determined. An improved calibration method is achieved in that the at least one virtual reference mark is projected on a reference surface, which can travel vertically by means of the raisable and lowerable carrier plate, and independently of the vertical position thereof.

The present application relates to a device for determining placements of pattern elements of a reflective photolithographic mask in the operating environment thereof, wherein the device comprises: (a) at least one first means configured for determining surface unevenness data of a rear side of the reflective photolithographic mask and/or surface unevenness data of a mount of the reflective photolithographic mask in a measurement environment that does not correspond to the operating environment; (b) at least one second means configured for determining placement data of the pattern elements in the measurement environment; and (c) at least one computing unit configured for calculating the placements of the pattern elements of the reflective photolithographic mask in the operating environment from the determined surface unevenness data of the rear side and/or of the mount and the determined placement data.

The instant disclosure discloses a reticle retaining system comprising an inner pod and an outer pod. The inner pod is configured to receive a reticle that includes a first identification feature. The inner pod comprises an inner base having a reticle accommodating region generally at a geometric center thereof and surrounded by a periphery region, and an inner cover configured to establish sealing engagement with the inner base. The inner base has a first observable zone defined in the reticle accommodating region correspondingly arranged to allow observation of the first identification feature. The outer pod is configured to receive the inner base. The outer pod comprises an outer base having a second observable zone defined thereon observably aligned to the first observable zone of the inner pod upon receiving the inner pod, and an outer cover configured to engage the outer base and cover the inner pod.

The techniques described herein enable a head-mounted display device to use a fiducial marker to identify an Internet of Things (IoT) device. The head-mounted display device can use the identifier to establish a network connection with the IoT device. For example, the identifier can include an Internet Protocol (IP) address, a Bluetooth address, a cloud IoT identifier (e.g., AZURE hub IoT identifier), or another type of an identifier. By using an electronic paper display, the IoT device can dynamically generate and display a new fiducial marker when a new identifier is assigned to the IoT device or is generated by the IoT device. Consequently, the head-mounted display device can detect the fiducial marker and extract the identifier for the IoT device from the fiducial marker so that the identifier can be used to establish a network connection with the IoT device.